Pushbutton array

ABSTRACT

An array of pushbuttons is formed as a one-piece molding with interconnecting flexible strips which allow for individual movement of each pushbutton. This process results in pushbutton switch assemblies which are economical and which may be placed in subscriber telephone sets without danger of misplacement of individual pushbuttons.

United States Patent Inventors Anthony Crisp Beadle New Barnet; GeorgeOwen Foot, Hertford, both of England Appl. No. 859,320 Filed Sept. 19,1969 Patented Oct. 12, 1971 Assignee International Standard ElectricCorporation New York, N.Y. Priority Sept. 23, 1968 Great Britain45089/68 PUSHBUTTON ARRAY 4 Claims, 2 Drawing Figs.

US. Cl 200/172 R 1nt.Cl l-10lh 3/12 130T Ti'el'd of 'SeaEEI .f 200i107R? 159 B, 86 R, 5, 166 J; 179/90 K [56] References Cited UNITEDSTATES PATENTS 3,120,584 2/1964 Grunfelder et al ZOO/166.1 X 3,308,2533/ 1967 Krakinowski 200/86 X 3,382,338 5/1968 Arseneault et al.. 200/159B 3,472,974 10/ l 969 McGough 200/5 Primary Examiner-H. 0. JonesAttorneys-C. Cornell Remsen, Jr., Walter J. Baum, Percy P. Lantzy, .1.Warren Whitesel, Delbert P. Warner and James B. Raden ABSTRACT: An arrayof pushbuttons is formed as a onepiece molding with interconnectingflexible strips which allow for individual movement of each pushbutton.This process results in pushbutton switch assemblies which areeconomical and which may be placed in subscriber telephone sets withoutdanger of misplacement of individual pushbuttons.

rususu'rrou ARRAY This invention relates to pushbutton-operated devices,and particularly to arrays of pushbuttons and methods of making sucharrays.

According to the invention there is provided an array of pushbuttonsformed integrally with flexible interconnecting strips and a surroundingframe, the configuration of .the interconnecting strips enablingindividual operation of each push button.

The invention will now be described with reference to the accompanyingdrawings, in which:

FIG. 1 shows a plan view of a pushbutton array arranged for the keystrip of a telephone set, and

FIG. 2 shows a perspective view of the pushbutton array shown in FIG. 1,with flexible strip connecting only one column of pushbuttons.

Referring now to the drawings the pushbuttons A are arranged in threecolumns and four rows, and are interconnected by flexible connectingstrips 8 which are formed integrally with a frame C. The strips aredesigned so as to be flexible in the direction in which the buttons areto be moved and stifi" enough to restrict unwanted movement in otherdirections. The connecting strips are also so arranged that when onebutton is depressed the effect on adjacent buttons is negligible. Otherpatterns of connecting strips can be designed to have the same effect.

The array shown can be incorporated in the assembly of apushbutton-operated device which forms the key strip of a telephone set.In the finally assembled key strip, downward pressure on each buttoncloses one or more contact means (not shown) which will allow thegeneration of a signalling code. Furthermore by careful design theconnecting strips can have sufficient stiffness to return the buttons tothe normal position when released, thereby acting as a return spring andso eliminating the need for button return springs in the pushbuttondevice assembly.

The frame C of the pushbutton array could be extended to form a boxlikestructure which would house some or all of the other components of thecomplete pushbutton device.

The material for the array will be chosen to give the necessary degreeof flexibility for the connecting strips with the ability to stand up tocontinual flexing over a long period of time, also having the necessaryfinish and durability for the buttons themselves.

The advantage of the form of construction described above is that thepushbutton array can be formed in one operation so that each button isin its correct position and will remain so during any further assemblyoperations. For most uses, particularly in a telephone set, a series ofnumbers, letters or other markings are required on the upper face ofeach button. Starting with individual buttons, the possibilities ofassembly error are considerable; buttons can be placed in the wrongposition, or two buttons bearing the same character can be included; inmany designs characters could be assembled with the wrong orientationand in any event special keyways or shapes have to be used to preventrotation. The abovedescribed array eliminates all these hazards.

The array can probably most advantageously be made by moulding inplastics material. The array can be marked as a whole either by awell-known marking process such as hot stamping; by including thecharacters in the mould; or by the use of a two-shot moulding process inwhich characters are moulded first and a second injection surrounds themwith the final form. In the latter case an additional advantage can beobtained by a choice of moulding materials; the markings and flexibleraster (i.e. the strips B and frame C) would utilize a material such aspolypropylene chosen for its durability to flexing, whilst the buttonscould be made from a harder wearresisting material.

Another possible method of manufacture would be to cover the tops of thebuttons transparent caps, so that markings on the button tops would beprotected. The use of such caps would a ain permit the use of a harderless flexible material for the utton tops. it would also permit someinterchangeability of markings; for example on a normal telephone setthere are recommended international layouts for the 1 l0 digits but thetwo buttons on either side of 0' digit in the bottom row have a varietyof uses and possible markings. it might be expedient on these buttons(or on all buttons) to put the markings on the plastic caps so that achoice of characters can be obtained dependent on the particular use ofthe buttons.

The buttons could be formed by plastics injection moulding, with theconnecting strips between the buttons serving as feeds. This wouldresult in a saving in the cost of moulding compared with using theinjection method for moulding individual buttons, where the individualbuttons have to be cut off and the remaining flash trimmed.

We claim:

1. A pushbutton arrangement including as components thereof a pluralityof arrayed pushbuttons, a plurality of flexible strips eachinterconnecting certain of said pushbuttons and a surrounding frame,said components integrally formed as a single unit with said stripssufficiently flexible and configured to enable depressive operation ofeach pushbutton.

2. A pushbutton arrangement as claimed in claim 1, in which the array ofsaid pushbuttons comprises a plurality of columns and rows in which thepushbuttons of a column are interconnected serially by surmounting on astrip and said strip includes a multiple step portion adjacent eachpushbutton to limit the effect of operation of one pushbutton on theother pushbutton in that column.

3. An arrangement as claimed in claim 2, in which all said individualstrips are similarly configured.

4. An arrangement as claimed in claimed in claim 3, Wherein saidconnecting strips are inherently resilient to restore a pushbutton toits normal position on release of depressive operating force thereon.

1. A pushbutton arrangement including as components thereof a pluralityof arrayed pushbuttons, a plurality of flexible strips eachinterconnecting certain of said pushbuttons and a surrounding frame,said components integrally formed as a single unit with said stripssufficiently flexible and configured to enable depressive operation ofeach pushbutton.
 2. A pushbutton arrangement as claimed in claim 1, inwhich the array of said pushbuttons comprises a plurality of columns androws in which the pushbuttons of a column are interconnected serially bysurmounting on a strip and said strip includes a multiple step portionadjacent each pushbutton to limit the effect of operation of onepushbutton on the other pushbutton in that column.
 3. An arrangement asclaimed in claim 2, in which all said individual strips are similarlyconfigured.
 4. An arrangement as claimed in claimed in claim 3, Whereinsaid connecting strips are inherently resilient to restore a pushbuttonto its normal position on release of depressive operating force thereon.